Rock-drill



(No Model.)

H. G. WILLIAMS.

UNITED STATES PATENT OFFICE.

HORACE GUERNSEY VILLIAMS, OF LYKENS, PENNSYLVANIA.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 475,910, datedMay 31,1892.

Application filed September 8, 1891. Serial No. 405,099. (No model.)

To all whom it may concern:

Be it known that I, HORACE GUEENsEY WILLTAMs, a citizen of the UnitedStates, residing at Lykens, in the county of Dauphin and State ofPennsylvania, have invented certain new and useful Improvements in Rock-Drills; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as Will enable others skilledin the art to which it appertains to make and use the same.

This invention relates to rock-drills; and it consists in the novelconstruction and combination of the parts by which the drill isactuated, as hereinafter fully described and claimed.

In the drawings, Figure 1 is a longitudinal section through the cylinderot therock-drill, taken on the line oc in Fig. 2. Fig. 2 is across-section through the cylinder and one of the air-valves, taken onthe line @j y in Fig. l. Fig. 8 is a cross-section through the pistonrodand distance-piece, taken on the line a c in Fig. 1.

A is the cylinder.

B is a long piston Working in the cylinder and provided with apiston-rod b at one end for connecting it to the drill or othermechanical device to be Worked by the piston. The piston-rod b isprovided with spiral fiat portions 2, which slide back and forth in acorrespondingly-shaped hole in a ratchet-Wheel 3. This ratchet-Wheel 3revolves in a chamber 4 in the distance-piece 5, which is bolted to thefront end of the cylinder. Astufiingbox 6 is secured to the front end ofthe distance-piece, and `that part of the piston-rod which passesthrough the stuiiing box is round. The ratchet-Wheel is prevented frommoving longitudinally by the shoulder 7 of the distance-piece and thecollar 8, arranged between the distance-piece and the cylinder. Vashers9 are arranged on each side of the ratchet-Wheel to reduce the friction.The ratchet-Wheel 3 is provided with pawls 10, sliding in bosses 1l onthe distance-piece. These pawls are adapted to permit the ratchetwheelto revolve in one direction and to prevent its return movement. Springs12 are provided for pressing the pawls into gear with the teeth of theratchet-Wheel, and 13 are caps screwed into the bosses 11 and adapted toguide the stems of the pawls and to adjust the pressure of the springs.When the piston is pushed forward, the piston-rod turns theratchet-Wheel; but when the piston-rod is pushed backward the pawlsprevent the ratchet-wheel from turning backward, and the flat spiralportions on the piston-rod cause it to be partially revolved, therebygiving the drill its necessary rotatory movement at cach instroke.

C are india-rubber buiers at each end of the cylinder. The cylinder-backcover and the other parts of the rock-drill, Which are not hereinafterdescribed, and Which are not shown in the drawings, are of ordinaryapproved construction.

D is the inlet for compressed air or steam, and CZ is a longitudinalpassage communicating therewith and formed in the side of thecylinder-casting.

E are the inlet-valves to the cylinder, resting upon the seats i" at theends of the passage cl, and c are the inlet-ports, extending from theunder side of the inlet-valves and entering the cylinder near its ends.The passage CZ is placed in the center and the ports c are arrangedlongitudinally upon each side of it in the cylinder-casting. Both theinlet-valves and their passages are exactly alike, and each inlet-valveis arranged at that end of the cylinder to which it does not pertain.Thus the valve E at the front end ot the cylinder admits the compressedair to the rear end of the cylinder and the valve at the rear end admitsthe compressed air to the front end of the cylinder. The object ot' thisarrangement is to obtain a large air-space between the under side ofeach inlet-valve and the cylinder. The air is compressed by the pistoninto these spaces, so that very great compression in the ends of thecylinder is avoided.

F are valves resting upon the seats F above the valves E, the holesthrough the seats F being a little larger that the valves E, so that thevalves E may project upward through the said holes and join onto thevalves F.

G are removable caps for closing the valve- -chambers g, and the saidcaps are secured to the valve-chambers in any approved manner. Thevalve-stems c slide in the guides f in IOO the cylinder and f in thecaps G; but the valves may be guided in any other approved manuel'.

H are small ports which connect the valvechambers g, above thevalves F,with the middle portion of the cylinder, and 'g' are bosses or pipes inthe passage d for the ports I-I to pass through. The ports H extendlongitudinally past each other in the cylinder-casting. Acircumferential groove b is formed in the piston, and thuis groove hasits length substantially equal to the distance between the ports H.

I are the exhaust-ports, formed through the side of the cylinder andprovided with an outlet-opening I. Small ports z' are also formedthrough the side of the cylinder, substantially in line with the ends ofthe ports H, and open into the said exhaust-ports I.

The action of the engine is as follows: Vhen the parts are in thepositions shown in the drawings and compressed air is allowed to enterthe inlet D, the compressed air raises the valves E and F at the frontend of the cylinder, because the diameter of the hole through thevalve-seat F is greater than the diameter of the valve E and because thechamber g above the valve F is in communication with the atmospherethrough the ports II and t', the groove b,and the exhaust-port I. Thecompressed air passes through the valve E, down the port e, into therear end of the cylinder and propels the piston in the direction of thearrow in Fig. l. The forward motion of the piston closes theexhaust-port I at the front end of the cylinder and also closes thesmall port Hat the rear part of the cylining the latter part of thestroke of the piston.

The forward motion of the piston also places the chamber g above thevalve F at the rear end of the cylinder in communication with theexhaust-port I at the front end of the cylinder directly after it closesthe small port H at the rear end of the cylinder. The piston,

however, continues its forward stroke after uncovering the exhaust-portat the rear end of the cylinder, because it moves with a very highvelocity and because it takes a certain space of time for the compressedair to raise the valves E and F and to rush from the passage cZ throughthe valve E and down the port e into the front end of the cylinder.Directly the piston arrives at the end of its for- Ward stroke it ispropelled rearwardly by the air compressed by it in the front end of thecylinder and in the port e, leading into that end, and by the compressedair which rushes in through the valve E. The piston returns to the rearend of the cylinder and will continue to reciprocate in the cylinder aslong as compressed air is supplied.

What I claim isl. The combination, with the cylinder and thelong-grooved piston sliding therein, of separate lift-valves restingupon seats at those ends of the cylinder to which they do not pertain,the said cylinder being provided with ports extendinglongitudinally pasteach other and connecting the said valves with theends 4of the cylinderto which they do pertain and having small ports also extending past eachother and adapted to relieve the pressure behind the said valves and topermit them to open automatically when the said small ports areuncovered by the piston in the cylinder, substantially as set forth.

2. The combination, with the pistonrod provided with spiral portions, ofa ratchetwheel mounted ou the said portions, the distancepiece inclosingthe piston-rod and ratchet-wheel and provided with a stuffingboX at itsfront end, the collar between the ratchet-wheel and the cylinder, thcwashers ou each side of the ratchet-wheel, and the spring-actuated pawlsadapted to engage with the ratchet-wheel, whereby the piston may bepartially revolved at each alternate stroke, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.i

HORACE GUERNSEY WILLIAMS.

lVitnesses:

J.- L. BRALLIER, M. DIcKERsoN.

